1. Field of the Invention
The present invention relates, to a method and apparatus for correcting a chromaticity diagram by a variable brightness, and more particularly to a method and apparatus for correcting a chromaticity diagram by a variable brightness in which an error value with respect to a first grid voltage during the adjustment of the white balance is obtained by reading the first grid voltage of a cathode ray tube (CRT) to correct a chromaticity diagram of red, green and blue.
2. Description of the Related Art
In general, among various peripheral devices for processing information in a computer, a display monitor is a device for displaying information as an image on a screen. Such a display monitor represents an image by emitting a fluorescent material coated on a surface of a CRT by an electron beam controlled by an image signal.
In such display monitors, a brightness control, operated by a user, adjusts the brightness on the display monitor by adjusting the grid voltage on a first control grid as the CRT.
Unfortunately, changing the brightness produces errors in the chromaticity diagram of red, green and blue of the CRT and it is therefore necessary to correct the chromaticity diagram if proper color characteristics are to be maintained.
The following U.S. patents each disclose color correction apparatus having some features in common with the present invention. However, none of these references teaches or suggests the specifically recited combination of the present invention: U.S. Pat. No. 4,962,418 to Kamaga, entitled Color Picture Display Apparatus, U.S. Pat. No. 5,146,323 to Kobori et al., entitled Signal Processing Circuit Including A White Balance Adjusting Circuit In A Color Video Printer Apparatus, U.S. Pat. No. 5,257,096 to Oshima, entitled Monitor Television Receiver, U.S. Pat. No. 5,303,071 to Kakimura, entitled Color Corrector In An Apparuts For Producing Color Image, and U.S. Pat. No. 5,311,294 to Cromer et al., entitled Method And Apparatus For Setting The Color Balance Of A Color Display Device.